POC: Add the Position class for GMT embellishment placement

pygmt/params/__init__.py

@@ -4,3 +4,4 @@
 
 from pygmt.params.box import Box
 from pygmt.params.pattern import Pattern
+from pygmt.params.position import Position

pygmt/params/position.py

@@ -0,0 +1,42 @@
+"""
+The Position class for positioning GMT embellishments.
+"""
+
+import dataclasses
+from collections.abc import Sequence
+from typing import Literal
+
+from pygmt._typing import AnchorCode
+from pygmt.alias import Alias
+from pygmt.params.base import BaseParam
+
+
+@dataclasses.dataclass(repr=False)
+class Position(BaseParam):
+    """
+    The class for positioning GMT embellishments.
+    """
+
+    location: str | tuple[float | str, float | str]
+    type: Literal["mapcoords", "inside", "outside", "boxcoords", "plotcoords"]
+    anchor: AnchorCode
+    offset: Sequence[float | str]
+
+    @property
+    def _aliases(self):
+        return [
+            Alias(
+                self.type,
+                name="type",
+                mapping={
+                    "mapcoords": "g",
+                    "boxcoords": "n",
+                    "plotcoords": "x",
+                    "inside": "j",
+                    "outside": "J",
+                },
+            ),
+            Alias(self.location, name="location", sep="/", size=2),
+            Alias(self.anchor, name="anchor"),
+            Alias(self.offset, name="offset", sep="/", size=2),
+        ]

pygmt/src/logo.py

@@ -7,14 +7,16 @@
 
 from pygmt.alias import Alias, AliasSystem
 from pygmt.clib import Session
-from pygmt.helpers import build_arg_list, fmt_docstring, use_alias
-from pygmt.params import Box
+from pygmt.helpers import build_arg_list, fmt_docstring
+from pygmt.params import Box, Position
 
 
 @fmt_docstring
-@use_alias(D="position")
-def logo(
+def logo(  # noqa: PLR0913
     self,
+    position: Position,
+    width: float | str | None = None,
+    height: float | str | None = None,
     projection: str | None = None,
     region: Sequence[float | str] | str | None = None,
     style: Literal["standard", "url", "no_label"] = "standard",
@@ -36,7 +38,12 @@ def logo(
 
     Full GMT docs at :gmt-docs:`gmtlogo.html`.
 
-    {aliases}
+    **Aliases:**
+
+    .. hlist::
+       :columns: 3
+
+       - D = position, **+w**: width, **+h**: height
        - F = box
        - J = projection
        - R = region
@@ -73,6 +80,11 @@ def logo(
     self._activate_figure()
 
     aliasdict = AliasSystem(
+        D=[
+            Alias(position, name="position"),
+            Alias(width, name="width", prefix="+w"),
+            Alias(height, name="height", prefix="+h"),
+        ],
         F=Alias(box, name="box"),
         S=Alias(
             style, name="style", mapping={"standard": "l", "url": "u", "no_label": "n"}